You know what they say, "Feed a fever, starve a cold." I say, dive in! Seriously, some people truly believe that eating minimally while sick reserves more energy for your body to use in healing itself (Dr. Andrew Wiel, for instance).
Look, chances are, the next few days are going to be rough anyway, so you might as well get it all over with at once. That's my opinion.
Btw, NyQuil comes in pill form without the sugar, so pick some up. I just took it last week and can attest that it is just as effective.
Good luck!